1. Field of the Invention
The present invention relates to a diffuser unit for air conditioning systems adapted to be mounted on the sidewall or ceiling of a house or building, a vehicle or the like.
2. Prior Art
A diffuser unit of this type is disclosed in Japanese Utility Model Laid-open Publication No. 60-34009. The disclosed diffuser unit includes an air supply duct having two air outlets adapted to be selectively opened and closed by a single damper disposed in the duct. When one of the air outlets is closed by the damper, the temperature controlled air is supplied solely from the other air outlet. When the damper is turned to an intermediate position, the air is blown-off from both air outlets. In this instance, the ratio of the flow rate of blown-off air from the one air outlet to the flow rate of blown-off air from the other air outlet is proportional to the angular position of the damper.
In an application in which the diffuser unit is mounted on the ceiling of a house or building, it is highly desirable that one of the air outlets is selected depending on the desired air conditioning mode and cold air or hot air is blown-off exclusively from the selected air outlet at a controlled flow rate while closing the other air outlet, thereby increasing the air conditioning efficiency.
However, such desirable air conditioning is not attained by the known diffuser unit described above because the flow rate of blown-off air from each respective air outlet is not controlled independently. Any angular movement of the damper to adjust the flow rate of blown-off air from the selected air outlet will necessarily cause the non-selected air outlet to be partially opened, thereby letting cold air or hot air pass through the non-selected air outlet. Due to this unintended air distribution, an efficient air conditioning is difficult to achieve.